2-[[[3-Methyl-4-(2,2,2-trifluoroethoxy)-2-pyridinyl]methyl]sulfinyl]-1H-benzimidazole or a salt thereof having an antiulcer action is reported in JP-A-61-50978, etc.
An anhydrous or hydrate crystal of optically active (R)-2-[[[3-methyl-4-(2,2,2-trifluoroethoxy)-2-pyridinyl]methyl]sulfinyl]-1H-benzimidazole is reported in WO2004/083200, WO01/87874, WO02/44167 and the like.
There is a demand for an antiulcer drug which is stable and superior in the absorbability.